GLOSSARY AND REFERENCE SECTION

The purposes of this section are threefold:

a. To act as a reference for the definition of any terms found in the text.

b. To serve as a general introduction to some of the terminology associated with sponges. To this end, the sections in

this glossary correspond to the headings found in the species descriptions. Within each section, the terms are then

arranged in an appropriate, logical sequence.

c. To indicate the terms available and the information that should be observed and noted when recording a sponge

specimen.

Where adequate and precise definitions have been previously published, these are reproduced verbatim. The main

sources are Borojevic, Fry et al., (1968) and Weidenmeyer, (1977). Other sources are noted in the text.

1. FORM.

1.1 Terms relating to the shape of the sponge.

The terms in this section are arranged approximately in order of increasing mass and/or

complexity of body form.

Boring

a. Some or all of the sponge is contained in

channels within a hard substrate such as

shell or limestone.

b. No basal attachment area. (e.g. the alpha

stage of Cliona celata.)

Thin sheets a. Growth predominantly lateral, resulting

in spreading sheets less than 3mm thick.

b. Attachment basal area continuous. (e.g.

Microciona atrasanguinea).

Cushions

a. Growth predominantly lateral, resulting

in spreading sheets between 3 and l0mm

thick.

b. Attachment basal area continuous. (e.g.

Myxilla fimbriata).

Massive-

lobose

a. Growth vertical and lateral but unequal,

greater than about 10mm; if growth is

predominantly vertical results in lobed

forms; if growth is predominantly lateral

results in ridged forms.

b. Attachment area matches greatest body

width e.g. Myxilla incrustans).

Massive-

globose

a. Includes forms which are globular,

hemispherical or disc-shaped.

b. Growth vertical and lateral.

c. Attachment basal area as much as

greatest body width (i.e. hemispherical) or

slightly less than greatest body width (i.e.

globular). (e.g. Polymastia boletiformis).

Massive-

pear a. Growth vertical and lateral but unequal.

b. Attachment basal area as much as, or

slightly less than, the greatest body width.

Massive-fig a. Growth vertical and lateral but unequal.

b. Attachment basal area less than the

greatest body width (e.g. Suberites

carnosus).

Massive-

flanged

a. Growth vertical and lateral but unequal.

Vertical growth can proceed at variable

rates, infilling the spaces between the erect,

flattened ribs or flanges of immature

sponge. Viewed from above, flanged crests

can either be regular, radiating out from the

centre like spokes of a wheel, or irregular,

set at angles to each other.

b. Attachment basal area corresponds to

greatest body width.

Cylindrical a. Includes forms which are tubular, club-

shaped, spindle-shaped.

b. Growth predominantly vertical and

columnar, but because it is more raised at

outer edges, a hollow centre is formed but

this becomes invisible when the apical

opening becomes reduced to an oscule, and

effect is closed. Hollow centre may later

become infilled so cylinder appears to be

solid and apical opening is no longer

apparent.

c. Cylinder may be circular in cross-section

or ellipsoidal when cylinder is laterally

compressed.

d. Attachment basal area less than the

greatest body width (e.g. Scypha ciliata).

Cuplike a. Includes forms resembling vases, funnels

and cups.

b. Edges of walls may be discontinuous, i.e.

may only be joined together at lower

margins, forming a notch, but here they are

treated as cups.

c. Growth predominantly vertical and

spreading, but because it is more rapid at

outer edges, a hollow centre is formed

which remains visible - effect is open.

d. Attachment basal area less than greatest

body width (e.g. Axinella

infundibuliformis).

Lamellate

a. Includes forms resembling fans

(flabellate forms) and flaps (i.e. vertical

sheets).

b. Includes erect fans lying in one plane, to

fans curved round to resemble cups or even

whorls, but whose free edges never join at

any point to form actual cups.

c. Growth is predominantly vertical.

d. Attachment basal area less than greatest

body width (e.g. Axinella flustra).

Branching-

repent

a. Branches may be simple or fused,

cylindrical or flattened in cross section,

solid or hollow.

b. Growth is predominantly horizontal.

c. Attachment basal area large in proportion

to body bulk, though it may not be

continuous (e.g. Haliclona simulans).

Branching-

erect

a. Branches may be simple or fused,

cylindrical or flattened in cross-section,

solid or hollow.

b. If growth is predominantly vertical,

results in erect and free forms (i.e. tree-

like), with regular or irregular branching. If

growth is predominantly horizontal, results

in semi-erect, free forms whose branches lie

parallel to the substratum. The stalk is

usually visible adding to the erect

impression, cf. repent.

c. Attachment basal area is small in

proportion to body bulk (e.g. Axinella

dissimilis).

1.2 Miscellaneous terms

These are some terms that might be encountered in the description of form (as well as in other

contexts).

Mesial/medial Of or situated in the middle.

Dichotomous Branching by repeated division into two roughly equal parts.

Polytomous Branching by division into more than two parts.

Anastomose To join or merge, e.g. as in branches which fuse together.

Stipitate Stalked.

Rooting tufts Processes anchoring the sponge into a soft substrate. Common in deep sea

sponges.

1.3. Sponge dimensions

Measure height, length and width (in cms). It is preferable to indicate these dimensions on a

sketch.

2. COLOUR

Despite the familiarity of the concept of colours the recording of colour without a basis for

comparative reference can be highly subjective. It is therefore strongly recommended that

colours are recorded with the assistance of the Methuen Handbook of Colour (Kornerup and

Wanscher, 1978). Many colour descriptions in the species sheets have not used this (or any

other) basis of reference, but we hope to standardise gradually on this book. In general many

sponges develop more pigment in high ambient light levels, so colour is variable both with

predominant water clarity, depth, and topographic position of the colony.

3. SMELL

Most marine sponges produce little smell out of water or, if they do, it is a general marine odour.

However, in a few cases, odours are emitted which can be distinctive, and may even be

diagnostic. Unlike people in the wine trade, spongologists have not evolved a vocabulary for

smell, which must for the time being be likened to other smells that are familiar.

4. SLIME

Many sponges produce mucus as a defence against the settlement of detritus, or other marine

organisms. The extent to which this slime is exuded on collection can be diagnostic. For

example, Polymastia boletiformis gives off no slime, Myxilla rosacea exudes a lot, Haliclona

viscosa is only obviously slimy when crushed, and Haliclona cinerea produces slime strands

when pulled apart. It is therefore important to record the amount of slime, and how it is exuded.

5. CONSISTENCY

Again, a language for consistency is still evolving. Terms used are everyday adjectives, but their

meanings in the context of sponge descriptions are given below. They should be qualified with

very, slightly, etc. as appropriate.

5.1 General Consistency

Soft Like wet cotton wool (e.g. Rhaphidostyla kitchingi).

Compact Firm and rubbery (e.g. Polymastia boletiformis).

Hard Treat as a quality distinct from firmness (see below). A hard sponge is one with a surface

like wood. (e.g. Haliclona simulans).

5.2 Reaction to pressure

Compressible Easily compressed (e.g. Dysidea fragilis).

Firm Requires considerable pressure to deform the sponge. Like the rubber of a car tyre. (e.g.

Pachymatisma johnstonia).

Incompressible Does not compress (e.g. Stelletta grubii).

Elastic How far does the sponge return to its original shape after compression? Like a bath

sponge if elastic (e.g. Dysidea fragilis).

Inelastic Where any deformation is retained (e.g. Pachymatisma johnstonia), and there is no

tendency to return to the original shape. Like 'styrofoam' used by flower arrangers to hold water

and plant stems.

5.3 Characteristics when torn or broken

Fragile Easily falls to pieces (e.g. Microciona armata).

Brittle Easily breaks (e.g. Haliclona simulans).

Tough Resistance to tearing: this property is in most cases covered by firmness (see above).

However, uneven distribution of strengthening tissues may lead to unexpected results which are

worth recording (e.g. Dysidea fragilis).

5.4 Characteristics when manipulated

Fleshy Tendency to be gelatinous with reduced or non-existent skeleton (e.g. Thymosia guernei).

Crumbly/Friable Easily broken into small pieces when rubbed between the fingers (e.g.

Halichondria panicea).

Slimy Mucus is apparent when sponge is rubbed between the fingers (e.g. Stelligera rigida). See

section 4 above.

6. SURFACE

6.1 Profile view

Even The gross surface profile has smooth lines, without marked

irregularities. (e.g. Pachymatisma johnstonia).

Uneven Opposite to above (e.g. some forms of Myxilla incrustans).

Wrinkled Parts or all of surface thrown into wrinkles.

Irregular

Folds

In some parts the surface fold over onto itself (e.g. some

forms of Hymeniacidon perleve).

6.2 Projections

Smooth No projections, hairs or depressions (e.g. Pachymatisma

johnstonia).

Tuberculate

Warty appearance caused by small rounded projections

(e.g. some forms of Stylostichon plumosum, Tethya

aurantium).

Conulate

Pyramidal cone-shaped projections, often caused by lifting

of surface due to protruding end of skeletal fibres (e.g.

Dysidea fragilis).

Fistulate Hollow, narrow, reed-like tubes, averaging less than 5mm

long (e.g. the smaller processes usually present on

Haliclona fistulosa).

Papillate Hollow, strap-like tubes averaging more than 5mm long

(e.g. Polymastia spp.).

Branching

processes

Longer, tassel-like, processes thrown off from the surface,

which may branch and/or anastomose (e.g. Amphilectus

fucorum, Haliclona fistulosa).

Oscular

chimneys

Mammillate to cylindrical surface projections bearing

oscules (e.g. Haliclona viscosa).

6.3 Hairs

Spinose Coarse, short, stiff, bristly hairs, usually widely spaced.

Hispid Long, closely-packed hairs.

Hirsute Rough, coarse, untrimmed hairs, shorter than hispid.

Villose Long, shaggy hairs, slender and soft but not matted; longer than

hispid (e.g. Stelligera rigida).

Velutinous Velvety; hairs dense, firm and straight (e.g. Suberites carnosus).

6.4 Depressions

Punctate Punctured; surface dotted with pin-point impressions (e.g.

inner surface of Axinella infundibuliformis).

Striated Marked with longitudinal or parallel lines (e.g. Adreus

fascicularis).

Sulcate Furrowed with longitudinal or parallel channels. (e.g. Mycale

lingua)

Polygonal

grooves Self explanatory.

6.5 Subsurface features

Canal

patterns

Subsurface exhalant canals are sometimes seen through the

surface (e.g. Microciona atrasanguinea).

Cavities These sometimes occur below, and show through, the ectosome

(e.g. Dysidea fragilis).

6.6 Feel

Granular Has a gritty feel (e.g. Pachymatisma johnstonia).

Leathery Feels like leather.

Slippery Negligible friction, may be caused by mucus (e.g. Homaxinella subdola ).

High friction Like a pencil eraser (e.g. Haliclona simulans).

Moderate friction Anything in between the previous two (e.g. Myxilla incrustans).

7. APERTURES

Ostium Any opening through which water enters a sponge.

Oscule (=osculum) An aperture through which water leaves a sponge.

Normally, ostia are small, sometimes not visible or obvious to the naked eye, whereas oscules

are prominent. It is important to note whether apertures are scattered, grouped, in a linear series,

or some other arrangement; their frequency; and whether they are open or closed before and after

collection.

8. CONTRACTION

Although certain sponges have been reported to respond to the presence of a diver underwater,

contraction usually occurs only on physical disturbance and/or removal from the water. Its

occurrence and degree should be noted - i.e. none, slight, marked.

9. SKELETON

Terms described in the first section are anatomical, and in the remaining sections are skeletal.

9.1 Anatomical Terms

Choanocyte

A cell bearing a flagellum, which

is surrounded by a collar of

cytoplasmic microvilli (i.e. finger-

like projections)

Choanocyte

chamber Any cavity lined by choanocytes.

Flagellated chamber

Synonymous with, but less

precise than, the previous term. It

is preferable to avoid using. it.

Ectosome Peripheral region of a sponge,

devoid of choanocyte chambers.

Choanosome A region of a sponge, containing

choanocyte chambers, i.e. loosely

the interior of a sponge.

Pinacoderm

A unistratified layer of cells, other

than the choanoderm delimiting

the sponge from the external

milieu.

Choanoderm A single layer of choanocytes.

Mesohyl

Everything constituting the

sponge between the pinacoderm

and the choanoderm.

Cortex

A layer of the ectosome

consolidated by a distinctive

skeleton.

Spherulous cells

Cells containing large, round

vacuoles, occupying most of the

cells.(e.g. Mycale similaris).

9.2 Skeletal components

Skeleton All structures of which the primary function is the consolidation and mechanical

protection of the sponge.

Spicule A discrete autochthonous element of the skeleton consisting mainly of silica or calcium

carbonate. (Autochthonous means they are indigenous to the sponge which has secreted the

spicules.) Section 10 (following) is a glossary of terms used to describe spicules.

Collagen The major structural protein of the animal kingdom.

Fibrillar collagen Fibrils of collagen dispersed throughout the intercellular matrix.

Spongin Proteinaceous horny skeletal material, either alone [as in bath sponges], or binding

siliceous spicules together [as in Haliclona or Microciona]. Another type of collagen.

Fibre A discrete column of spongin, either without spicules, (e.g. Aplysilla) or cored by

indigenous spicules (e.g. Haliclona) or filled with foreign spicules and/or debris (e.g. Dysidea).

In some sponges (e.g. the Haplosclerids) the distinction is made between primary fibres, which

run perpendicular to the surface, and secondary fibres, which run parallel to the surface.

Tract A column or (rarely) single line of bundled, overlapping, or aligned monaxonic

megascleres, with or without spongin cement.

9.3 Skeleton Arrangements

Ascending Used mainly of fibres and tracts (q.v.), where they extend to the surface and end

orientated perpendicular to it (equivalent to 'vertical').

Echinating Literally covered with spines, bristles, or bristle-like outgrowths. In the context of

sponge skeletal arrangements, the term is used to describe monactinal spicules standing off, or

projecting from, another structure.

Palisade Spicules arranged like a fence.

Plumose fibre, column A fibre or column usually ascending, with monaxon megascleres

radiating obliquely upward from the axis, points outwards; these columns commonly

anastomose; they characterize axinellid structure.

Radiate structure Skeletal architecture characterized by megascleres oriented radially from the

centre of the sponge, and commonly by lack of spongin.

Isotropic reticulation Reticulation which is disorientated, random, and in which there is no

distinction of primary and/or secondary fibres or tracts.

Isodictyal reticulation Isotropic reticulation in which the meshes are commonly triangular in all

directions, outlined by single monaxon megascleres which are joined at their tips, with spongin

cementing the nodes.

Anisotropic reticulation That type of reticulation which is oriented with respect to the surface,

and in which either primary, or secondary fibres (or tracts) or both can be distinguished.

Plumoreticulate Plumose columns arranged in a network.

9.4. Skeletal Arrangements Implied by Reference to Taxa

Choristid From the Order Choristida (replaced by Astrophorida in the classification scheme

used in this Guide). The type of skeletal architecture distinguished by predominantly radiate,

occasionally confused, arrangements of megascleres including triaenes with cladomes outward,

by lack of spongin, and commonly by a cortex. Halichondroid From the Order Halichondrida.

The type of skeletal architecture characteristic of Halichondria and some other sponges, i.e. with

megascleres arranged in vague tracts which may be reticulate; or scattered in sheets between

alveoles and stouter ascending tracts. In sections the spicules often appear as a disorganised,

criss-crossing mass.

Hymedesmoid From the genus Hymedesmia. In encrusting sponges, that part of the skeleton

consisting of large primary acanthostyles perpendicular to the substrate, and smaller

acanthostyles echinating the substrate.

Renieroid From the Genus Reniera in the Family Haliclonidae. The type of reticulate structure

as in Haliclona (Reniera), i.e. an anisotropic reticulation of diacts which is commonly

unispicular, with spongin at the nodes; or with ascending tracts within an isotropic or anisotropic

interstitial reticulation of single diacts.

10. SPICULES

Because the types, shapes

and sizes of spicules tend

to be consistent within a

species, they are very

important characters for

sponge classification. Their

great variety has attracted a

complex nomenclature,

unfortunately not entirely

avoidable. However, this

glossary is restricted only

to spicules mentioned in

the species descriptions.

Various narrative

definitions are given

below, but the essence of

the glossary is in the

figures on the right as the

authors feel that direct

visual comparison is

always far better than

complex jargon. On the

whole, it was felt

unnecessary to supplement

these figures with turgid

and precise definitions, and

this has largely been

avoided. Terms appearing

below either do not occur

in the figures (but do in the

text), or are included to

clarify the figures where

this was felt to be

necessary.

Monact(inal) Any spicule (megasclere or microsclere) having one ray, which grew from one end

only; with ends fundamentally different in form. The four spicules to the upper right (fig. 1) are

monacts.

Diact(inal) Any spicule (megasclere or microsclere) having two diverging rays; being

commonly but not always bilaterally symmetrical (with conforming ends). The six spicules to the

upper left (fig. 1) are diacts.

Monaxon Any linear, non-radiate spicule; or a spicule type never having more than two rays

along one axis. This collective term includes both actinal and diactinal spicules. Thus all the

spicules on the upper row (fig. 1) are monaxons, as are the microrhabds and sigmatoscleres in

fig. 2.

Triact(inal) Any radiate spicule (megasclere or microsclere) having three rays. Such spicules are

most frequent in Calcarea, rare in Hexactinellida (as reduced hexacts) and in Demospongia (as

reduced tetraxons).

Triradiate Synonymous with triact - used in this Guide to describe calcareous spicules.

Tetract(inal) Any radiate spicule (megasclere or microsclere) having four rays. The lower row

of spicules (fig. 1) are tetracts.

Quadriradiate Synonymous with tetract - used in this Guide to describe calcareous spicules.

Acantho- Prefix meaning spined. Acanthostyles occur frequently in the sponges in this guide.

Tylote A diactinal megasclere with a tyle on each end. Also an adjective meaning provided with

one or more tyles. A tyle is any rounded swelling or knob in a spicule, other than the centrum.

(Note that a centrum is the globular centre of many euasters).

Centrotylote A median swelling (tyle) in a spicule. See centrotylote oxea, and centrotylote

microxea on right. (e.g. Suberites ficus)

Polytylote A spicule with a series of swellings along the shaft. (e.g. styles of Polymastia

conigera)

Megasclere The larger spicule types, comprising the major structural elements of a sponge

skeleton. All spicules illustrated in fig. 1 are megascleres.

Calthrops Tetraxon megasclere with equal rays arranged normal to faces of a tetrahedron. The

point to note is the symmetry of calthrops spicules. (e.g. Dercitus bucklandi)

Triaene Any tetraxial, tetractinal megasclere having one unequal ray (termed rhabd) which is

commonly much longer than the other three (known as clads, together forming the cladome),

occasionally shorter, or modified (see Stelletta grubii).

Microscleres Relatively

very small spicules of

various forms,

characteristic of certain

sponges. The following

four definitions are for the

categories of microscleres

encountered in this Guide.

The spicules illustrated in

fig. 2 are all microscleres.

Microrhabds A collective

term for monaxonic

microscleres, excluding

sigmatoscleres and

spiroscleres. Among the

simple forms are microxea,

microstrongyle, microstyle

(comma), raphide; among

the ornamented (e.g.

spined) forms are

sanidaster and its variants,

which were once regarded

as asters.

Sigmatoscleres A group of

monaxon microscleres

including sigma and its

variants. See the central

group of spicules in fig. 2.

Streptoscleres A

collective term comprising

streptasters with the

exclusion of sanidaster and

its variants. See the left of

the bottom row of fig. 2.

Euasters A collective term

for astrose microscleres in which the actines radiate from a centre; with or without a centrum.

See the right of the bottom row (fig. 2).

Spheraster An euaster with short rays and a thick centrum. The diameter of the centrum exceeds

the length of the rays. The rays may be pointed (oxyspheraster), strongylote

(strongylospheraster), or tylote (tylospheraster). See the oxyspheraster in fig. 2.

Chelae The drawings of chelae in this publication

have been prepared from Scanning Electron

Microscope images, which reveal their true shape. As

silica is transparent, however, they often appear to

have different shapes under the light microscope. The

alae of chelae are very thin, so usually the shape that

is seen depends on the angle at which they lie to the

microscope. The supporting structures beneath the

alae (falces) are usually more obvious because of their

thickness.

Picton, B.E., Morrow, C.C. & van Soest, R.W.B., 2007. [In] Sponges of Britain and Ireland

http://www.habitas.org.uk/marinelife/sponge_guide/glossary.html